1. Field of the Invention
The invention relates to a method for polishing a substrate composed of semiconductor material, comprising at least two steps. One step is a polishing step by means of which the substrate is polished on a polishing pad containing an abrasive material bonded in the polishing pad.
2. Background Art
WO 99/55491 A1 describes a two-stage polishing method, comprising a first polishing step, in which the substrate is polished on a polishing pad containing an abrasive material bonded in the polishing pad. A polishing step in which such a polishing pad—also called “fixed-abrasive pad”—is used is referred to hereinafter as “FAP” step for short. The subsequent second polishing step of the two-stage polishing method is a chemical mechanical polishing of the substrate on a polishing pad containing no bonded abrasive material. Abrasive material is introduced in the form of a slurry between the substrate and the polishing pad. Such a polishing step is referred to hereinafter as a “CMP” step for short. CMP is used in the two-stage polishing method of WO 99/55491 A1 in particular to eliminate scratches left by the FAP step on the polished surface of the substrate.
EP 1 717 001 A1 is one example where FAP steps are used when polishing semiconductor wafers which have not yet had any component structures formed upon their surface. During the polishing of such semiconductor wafers, it is primarily important to produce at least one lateral surface which is particularly planar and which has a minimal microroughness and nanotopography.